Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thanh lap » thanh san, phan lap, thanh hai
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thanh do » thanh de, thanh pho, thanh hoa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach y nang ma hoi. hieu van nam thuc vat ((thanh lap) or (thanh do)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y nang ma hoi. hieu van nam thuc vat ((thanh lap) OR (thanh do)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach y nang ma hoi. hieu van nam thuc vat ((thanh lap) or (thanh do)) cua tre*.